Sterile packages



N0V 8, 1960 J. K. LLOYD STERILE PACKAGES Filed oct. 1o, 195e uA/Onu 2 v I J ite rates Ptent Y STERILE PACKAGES John K. Lloyd, Skokie, Ill., assiguor to The Kendall Company, Boston, Mass., a corporation of Massachusetts Filed ocr. 1e, 1956, ser. No. 615,090

`s claims. (ci. zot-53.3)

This invention is concerned with flexible, non-frangible hermetically sealed internally sterile packages, particularly such packages wherein one or more fully flexible sterile catgut sutures of the non-boilable type are contained together with catgut suture llexibilizing fluid but more generally wherein any such internally sterile packages are maintained immersed in sterilizing lluid,

As used in this application the expression llexibilizing fluid refers to any fluid containing an agent (herein called a flexibilizing agent), capable of rendering a catgut suture more llexible, whereas sterilizing fluid refers to any fluid having continuing capacity to destroy bacteria and bacteria spores.

Surgical sutures are strong threadlike strands of various materials which are used in sewing or suturing in human and animal bodies to close open wounds. Such sutures, because they actually penetrate the llesh, must necessarily be completely sterile. Otherwise infection of the wound area is highly probable. As a matter of fact, the sterility of sutures is so important that the entire suture package is usually made sterile so that danger of contamination from the package is avoided.

Surgical sutures may be divided into two broad classes, those sutures which are absorbed and those which are not. Non-absorbable sutures generally are of such materials as cotton, linen, silk and the like, which may be sterilized and used in the dry condition. This invention is not concerned with such sutures.

Absorbable sutures on the other hand are prepared from long fibered animal proteins. An overwhelming majority of such sutures are prepared from animal intestines, particularly sheeps intestines. Catgut sutures, as these animal intestine sutures are commonly called, are easily deteriorated by heat in the presence of moisture to the point WhereV they are entirely useless. But catgut in the dry condition is stiff and Wiry and must be flexibilized before it may be used for suture purposes. These circumstances have led to the development of two types of absorbable sutures, boilable sutures and non-boilable sutures, both of which have been marketed in sealed glass tubes of ampoules.

Boilable catgut sutures in they tube are completely free of catgut flexibilizing fluid and hence must be made more flexible by the use of a fluid containing a flexibilizing agent (normally sterile water) prior to use. Non-boilable catgut sutures, on the other hand, are tubed together with adequate catgut llexibilizing fluid and hence are fully flexible and ready for instant use upon removal from the tube. But tubes containing non-boilable sutures in contrast to tubes containing boilable sutures can not have their exterior surfaces sterilized by boiling water since the temperature involved would deleteriously affect and make useless the contained suture in the presence of exibilizing uid. Tubes containing non-boilable sutures, therefore, are exteriorly sterilized, and kept sterile thereafter, by non-heat methods as by immersion in a sterilizing fluid of continuing sterilizing capacity as for example, a formaldehyde, alcohol and water solution.

ice

Hermetically-sealed glass ampoules have provided unique non-boilable suture containers in some respects because glass, due to its complete lack of moisture vapor transmission, retains the contained suture exibilizing solution intact, thereby keeping the catgut suture in fully llexible condition indefinitely.

Hermetcally-sealed glass ampoules also have been unique in that they are subject to substantially no osmotic action when tubes containing catgut flexibilizing fluid are immersed in sterilizing uids of continuing sterilizing capacity. Such sterilizing uids contain agents powerful enough to destroy spores as well as bacteria but, unfortunately, the agents are also destructive of proteinaceous catgut sutures. Glass so effectively prevents osmotic action, however, that combination shipping and storage containers are normally supplied wherein up to three dozen glass suture tubes each containing suture flexibilizing fluid are stored immersed in sterilizing lluid for long periods of time with no evidence of osmotic action.

But glass ampoules, although they have been the standard containers for llexible non-boilable sutures since the turn of the century, have well recognized deficiencies which are inherent in the rigid, frangible nature of glass. Such ampoules must be broken when the suture is to be used, with the result that fragments of glass may pierce the sterile gloves of the operating nurse destroying the sterile environment and perhaps temporarily incapacitat ing the nurse while cuts are treated and gloves are replaced. In addition, the suture itself may become irnpregnated with glass bits which may cut the strands or be carried with the suture into the patients body.

These deficiencies of glass ampoule containers for sutures have caused a great deal of activity directed toward substituting non-frangible materials, particularly llexible plastics of various kinds for glass as suture container material, No exible plastic has yet been discovered, however, which even approaches glass in lack of moisture vapor transmission and prevention of osmotic action. The result is that when liexible plastic containers are used as the sole containers, their moisture vapor transmission rates are sutficiently high that, under normal storage conditions, the packages lose their contained suture ilexibilizing fluid short of commercially feasible periods of time so that the contained sutures thereafter are no longer moist and fully llexible. Fur* thermore, Where llexible plastic containers are immersed in sterilizing uids in other containers, osmotic action takes place with the result that sterilizing agents intended for sterilizing the outside of the liexible plastic container, enter the container at best within a matter of three or four months to attack the suture itself.

Still another serious disadvantage, stemming from osmotic action when flexible plastic containers are used for sutures to be immersed on a continuing basis in sterilizing fluid, is that the fluid ins-ide the llexible plastic container and that outside eventually become the same. It, therefore, is necessary in using exible plastic containers to select a sterilizing uid which not only contains no agent which might harm the suture but one which contains a precise amount of water or other catgut ilexibilizing agent. This is the case both initially, and on a con tinuing basis, if the water or other flexibilizing agent content of the sterilizing Huid varies due to evaporation or other phenomenon. Otherwise the percentage of water or other ilexibilizing agent within the package may become either too low to impart proper flexibility to the catgut suture, or worse still, so high as to very materially damage the strength of the suture. Obviously, regulation of the water or other flexibilizing agent content of the sterilizing uid on a continuing basis would be a serious inconvenience to hospital personnel.

A The suture industry, then, has failed to supply the surgical demand for a non-frangible easily openable container for non-boilable sutures which either could be stored immersed in' an effectivesterilizing uid orV a uid of variable catgut liexibilizing agent content. Nor has the industry supplied an individual non-frangible easily openable container which alone could preserve a catgut suture, fully flexibilized, until such time as it could be utilized.

I The industry has also failed to provide non-frangible, Aeasily openable packages for sterile powders and liquids wherein the exteriors of the packages could be maintained in sterile condition by continuous immersion in sterilizing fluids.

It is, therefore, an object of this invention to provide an easily openable, exible, non-frangible package containing a sterile non-boilable catgut suture together with suture fiexibilizing fluid, the package having such a minute loss-rate of suture fiexibilizing fluid that the suture remains fully liexible for long periods of time.

It is a further object of this invention to provide an easily openable double package wherein one or more iiexible non-frangible inner envelopes each retaining a sterile non-boilable catgut suture fully flexible over long periods of time, together with sterile suture flexibilizing iiuid are contained in an outer container, the inside of the latter being essentially dry with the outside of the inner envelopes and the inside of the outer container being sterile if desired.

It is a still further object of this invention to provide an easily openable outer container containing one or more non-frangible flexible envelopes each containing a sterile suture, the entire container except for suture fiexib-ilizing fluid absorbed in the sterile catgut suture and in additional absorbent material within the container being essentially dry, the sutures remaining fully flexible for long periods of time, the entire contents of the outer container and its own inside surface being sterile if desired. AAnother important object of this invention is the provision of a double package for sutures, the outer package containing a sterilizing liuid and one or more sterile, easily openable, non-frangible inner envelopes, the inner envelopes, each containing one or more fully exible catgut sutures, being so impervious to the passage of sterilizing iiuid or agents that the sterile catgut sutures remain fu'ly flexible and commercially usable for long periods of time.

Another important object of this invention is the provision of a double package for sterile liquids or powders, the outer package containing a sterilizing fluid and one or more sterile easily openable non-frangible inner envelopes each containing a sterile liquid or powder, the envelopes being so impervious to the passage of sterilizing fluid that the contents remain substantially unmodified by such fluid for long periods of time.

Other objects of this invention will be apparent from a study of the specification, drawings, and claims.

In the drawings:

Figure 1 illustrates one example of a hermetically sealed laminar envelope package in accordance with this invention with portions cut away to show the enclosed sterile catgut suture and the sterile catgut suture flexibilizing fluid.

Figure 2 illustrates a cross-section of the envelope of Figure 1.

Figure 3 shows a modification (also cut-away) of the package of Figure l where-in the suture and the suture fiexibilizng fluid are contained in a sealed plastic envelope.

Figure 4 is a cut-away modification of the package of Figure 1 wherein excess sterile catgut suture fiexibilizing iiuid is absorbed in sterile absorbent material and the flexibilized suture is contained in an inner package.

Figure 5 is a cut-away modification of Figure 3 wherein the suture and the suture reel have absorbed the sterile catgut suture flexibilizing iiuid and wherein the outer package is bare metal foil united at the peripheral edges with the film.

Figure 6 illustrates a number of the packages of any of Figures 1, 3, 4 or 5 or similar packages containing sterile liquid or powder, submerged in sterilizing fluid inside a shipping and dispensing container.

Although films alone are practical as packaging material for moist flexible catgut sutures for only very limited periods of time, I have discovered that by proper selection and unification of film and metal foil, an excellent easy openable liexible package may be made which, when hermetically sealed, retains the suture in moist flexible condition for long periods of time in the presence of suture flexibilizing fiuid. The invention provides, for the first time, such a practical non-frangible package for moist sutures,

I have discovered that suitable metal foils of about .001 inch thickness and greater have sufiiciently low moisture vapor transmission rates that they may be made into practical packages suitable for storing moist fully fiexible catgut sutures provided that at the joints, the foils are properly united.

This may be accomplished for instance by inserting a suitable thermoplastic lm, die-cut to conform to the foil package edges and thereafter heat-sealing the two pieces of foil to the film around the periphery. As a practical matter, however, the foil frequently becomes contaminated during manufacture of packages therefrom with oil and other foreign matter which interferes with uniformly perfect sealing. I prefer, therefore, to flame-clean the foil immediately before it is joined to the film, a step which is best done before the material is formed into package units. It is preferable, however, to protect both layers of foil forming a package by hot extruding a film directly onto the foil immediately after dame-cleaning the latter. As a matter of fact, I prefer the simplicity of overall hot extrusion lamination of film to foil though the foil is in the range of thickness of .001 inch and more where overall lamination provides no appreciable additional impermeability.

My preferred package is one in which the metal is in sumcient thickness (.001 inch and over) that for all practical purposes the moisture vapor transmission rate and osmosis rate through the foil is insiginlicant. Packages of vsuch thick foil have the very lowest osmosis rates and moisture vapor loss rates. I prefer that the seal thickness be as small as possible consistent with good sealing of the film both to the foil and to itself and that the seal around the edges have a width of between and 250 mils or more.

This invention provides for the first time flexible, nonfrangible, easily openable packages which may be sterilized and stored immersed in sterilizing liuid for long periods of time without appreciable penetration of the packages by sterilizing liuid components.

For example, to illustrate the advantages of the foilii'm packages of my invention, the following comparison may be made. An open suture package may be prepared from two squares of 2 mil (.002 inch) polyethylene film, measuring 21/2 inches on a side, by superimposing the squares and heat-sealing them together on three side edges preferably with a 1A; inch wide seal. A similar open suture package may be made from two squares of 2 mil polyethylene film which has been melt extruded onto dame-cleaned 11/2 mil aluminum foil by superimposing the squares in film to film relationship and heat-sealing around three edges with a 1i-inch wide seal.

Ten each of film packages and foil-film packages were made up as above and into each, similar amounts of ilexibilizing iiuid and similar catgut sutures were placed whereupon the fourth side of each package was heat-sealed in the same manner as the other sides. The twenty packages were then immersed in the same sterilizing solution containing 1% formaldehyde. After one week no formaldehyde could be detected upon opening five of the foilfllm packages. But upon opening five of the film packages after one week, the suture in each package was appreciably tanned by the penetration of formaldehyde into the package although the sutures were still useable.

After weeks the remaining foil-film laminate packages were opened and still no formaldehyde could be detected inside any of the packages Whereas suflicient formaldehyde had penetrated the five remaining film packages to render the catgut suture unusable in that its was markedly reduced in strength and was almost completely indigestible. In addition, there were portions of the catgut which appeared to be somewhat brittle.

On a theoretical basis the foil-film package would appear to be several thousand-fold more resistant to osmosis and moisture vapor loss than the film package. Ignoring the amount which would pass through the seal edge, the film package would have 4 square inches of surface on each side or a total of 8 square inches of surface exposed to the transfusion of formaldehyde or other agents or fluids in the sterilizing fluid. On the other hand, the foil-film package (since the foil itself is impervious) would expose only the edges of the film seal to the sterilizing fluid surrounding the package. These edges in the instant case are made up of two layers of 2 mil polyethylene which would be somewhat reduced in sealing. But ignoring the reduced thickness resulting from heatsealing, at most the edge area of the seal presented to the sterilizing fluid would be l0 inches long and .004 inch wide, or .04 square inch. In other Words, the foilfilrn package exposes to the sterilizing fluid only 1/200 of the film area exposed by the film package.

In the matter of thickness through which the sterlizing fluids and agents would have to penetrate, the film package offers a thickness of only .002 inch, whereas the foiliilm package offers a thickness through the heat-seal width of .25 inch, a thickness 125 times greater.

One may logically assume from such calculations that the foil-film package is at least 25,000 times (125 200) as resistant to osmotic action and moisture vapor loss as the film package employing the same thickness of the same film in each case.

Obviously, since the suture preserved in the film package remains usable after the package has been immersed for a Week in sterilizing solution, particularly a solution containing formaldehyde, an immersed foil-film package may be expected to preserve a similar suture for a greatly extended period of time.

As a matter of fact, the foil-film package has proven itself so impervious with respect to penetration of fluids and such sterilizing agents as formaldehyde as to provide for the first time a means whereby flexible easily openable packages containing sterile liquids and powders may be subjected to external treatment and storage in sterilizing fluids for long periods of time Without deleterious effects on the sterile contents.

I have further discovered that with metal foil in the range between .0001 and .001 inch thickness, Where the foil is not completely impervious, sufliciently low moisture vapor transmission rates may be imparted to the foil by laminating it directly in overall, face-to-face relationship to one of various films in proper thickness as hereinafter described such that the composite may be made, into packages which although not preferred for extended storage of fully flexible catgut sutures are entirely suitable for less extended periods of storage of such sutures.

The preferred metal for the foil utilized in the products of this invention is aluminum, but tin, copper, and other non-toxic metals capable of being sheeted out into fo-ils from .0001 to .002 inch thickness, depending upon the metal used, are satisfactory. In general, the more malleable the metal, the thinner the foil may be. With commercial aluminum I have found a foil thickness range of between .00025 and .002 inch is entirely satisfactory for the purposes previously defined. -Foils in excess of 6. .002 inch, while they are suitable, possess no particular advantages and have the disadvantage ofk being somewhat less flexible.

The film portion to be united directly to the foil should be substantially moisture impervious organic non-hydrophilic film which is substantially insoluble in sterilizing or suture flexibilizing fluids with which it may come in contact in normal use.

In general, I prefer films which may be hot-extruded directly onto the foil and which are capable of being heat-sealed to themselves since heat-sealing provides the quickest, most convenient and undoubtedly the most satisfactory method of closing the package. But hot or cold gluing or hot or cold solvent or emulsion sealing or other methods of forming an adhesive closing seal for the foil or film-foil laminate package may be utilized so long as the sealing material is also substantially insoluble in the liquids with which it comes in contact in the finished package.

In general, where heat is to be employed in sealing the film to the foil or when two pieces of film-foil laminate are to have their film surfaces sealed together by heat, it is desirable to utilize film which is substantially unstretched in any direction since stretched film tends to shrink or retract in the heated area. Heat-scalable substantially crystalline films are suitable, however, and in particularly instances may even be preferred. But where film may exist at normal room temperatures either in the substantially crystalline or substantially non-crystalline` state depending upon its pre-treatment, it is generally preferred that the non-crystalline state exist since normally such films may be heat-sealed more readily or at much lower temperatures than would be required for the crystalline state. Films, for example, of polyethylene terephthalate may be hot extruded as molten polymer onto flame-cleaned foil and immediately thereafter quenched to room temperature thus providing a polyethylene terephthalate film-foil laminate in which the film portion is substantially non-crystalline.

Certain laminated films or film-forming materials are satisfactory with all of the usual flexibilizing fluids normally associated with sutures such as water, lower alcohols, xylene and acetone, and with the usual sterilizing fluids such as Water, formaldehyde, alcohol solutions. For example, such films may be prepared from the following materials:

Alcohol insoluble polyamides. Urea formaldehyde resins. Phenol formaldehyde resins. Melamine formaldehyde resins. Polytrichlorofluoroethylenes. Polyethylene terephthalates.

Other films may be successfully used with usual sterilizing fluids and with Water, lower alcohols and xylene but not with acetone. Examples of this group are of such materials as:

Polymers and copolymers of vinyl esters. Polymers and copolymers of vinylidene esters.

Still other films are suitable with usual sterilizing fluids and with Water and lower alcohols but not with xylene or acetone. Examples of this group `are of such materials Plasticized rubber hydrochloride. Polyacrylic polymers. Butadiene-styrene copolymers. Butadiene-acrylonitrile copolymers.

An example of a suitable material Which may be used with usual sterilizing fluids and with water, lower alcohols and acetone is polyethylene.

Where the film portion to be laminated to the metal foil is capable of hot extrusion, I prefer to extrude the hot material in the form of a film onto the flame-cleaned foil and immediately thereafter to chill the laminate. However, where that method cannot be utilized, the flame-cleaned foil may be coated with film-forming material from hot or cold solvents, emulsions, plastisols or organosols, such coatings being fused when necessary to provide continuous tilm surfaces in the area coated.

Where the iilm portion of the laminate is capable of forming heat seals, regardless of the method of forming the laminate, and whether the laminate extends over the entire foil surface or only at the package borders, heatsealing is the preferred method of sealing. Open packages are rst formed of the laminated material and these packages are then sealed after being filled.

Where an overall laminate in which the film portion is not heat-scalable is provided, the borders of the sheets forming the package must be coated with additional material or the film already a part of the laminate must be made adhesive at the time when the open package is made and again when the package is sealed. Where only the bordering portions of the package are to be coated with such material it may all be applied at the times when the package joints are being made but such procedure is not recommended.

Other films which may not easily be united directly to the foil may be laminated using one of the materials previously described, as an adhesive but in general such materials which have to be adhered by another material Iare more difticult to utilize and do not add materially to the utility of the package.

The minimum thickness of the film to be laminated to the foil increases as the foil thickness decreases starting from about .0003 inch thick film with thick impervious .001 to .002 inch foil and increasing as the foil thickness decreases to the upper practical limit for film flexibility at about .01 inch. I have found with thin foils such as a .00035 inch thickness of aluminum, a iilm of polyethylene heat-extruded onto tiame-cleaned foil forms an entirely satisfactory package material for purposes of this invention for restricted but practical periods of time where the lm is as little as .0005 inch thick but I prefer a polyethylene lm of .0015 to .0035 inch thickness because increased shelf life is obtained for these thin foiled packages by sacrificing only a small amount of the exibility. In general, it is commercially desirable that a catgut suture package have a shelf-life of at least a year. Assuming a moisture vapor transmission rate of 1.2 milligrams per square inch per week for the thin foil united lrn-foil combination, such a package of about 20 square inches total outside area would lose approximately 1250 milligrams of liquid in a year. This would mean that the package should contain at least 1.5 cubic centimeters of catgut suture liexibilizing tiuid when manufactured in order to preserve the suture fully liexible during the entire year. As would be expected, increasing the catgut suture exibilizing liuid without changing the total outside area of the package of decreasing the outside area without changing the amount of iiuid increases the shelf-life of the packaged fully iiexible catgut in proportion but excessive liquid presents a disposal problem when the package is opened. Obviously, increasing the foil thickness also increases the shelf-life up to the point where the foil becomes impervious at about .001 inch thickness.

Referring now to the drawings:

In Fig. 1, an example of a bacteria impervious sealed united film-foil envelope package 10 is shown broken away to show the layer of foil 14 and the layer of iilm 15 united to it. The broken open portion also reveals the sealed area 26 and the contents of the package comprising a fully iiexibilized non-boilable catgut suture 11, a suture reel 12, and the catgut suture exibilizing liuid 13.

If desired, the preferred form of the ilm-foil envelope may be altered considerably without departing from the invention. For example, the envelope may be folded and sealed around the edges of the overlapping surfaces. A particular example of such construction is a package vwherein only one fold is made so that the overlapping portions of the sheet have substantially superimposed straight edges. Such a package might be sealed only along the superimposed cut edges or it might be seale'd along all edges including the folded edge.

Fig. 2 shows how the particular package of Fig. l is formed, layer 15 being heat-extruded onto layer 14 with the edges of the package being preferably heat-sealed together. This construction is not, of course, essential.

In Fig. 3, a modilication of the package of Fig. 1 shows the catgut suture 11 and the reel 12 enclosed with the catgut suture flexibilizing fluid 13 in a sealed envelope 16. The advantage of this modification is that the suture is contained in a wholly sterile envelope. The moisture vapor transmission rate of the inner envelope 16 is immaterial since the outer envelope 10 forms the real moisture transmission barrier. I prefer a heat-sealed transparent lilm envelope for envelope 16, but any material not dissolved by the tiexibilizing fluid may be used. There is a special advantage, however, in films and other sheet materials which permit passage of ethylene oxide and similar gaseous suture sterilizing agents. These agents may be incorporated into catgut suture liexibilizing uids in limited amounts in accordance with US. Patent No. 2,736,059 to sterilize the suture in the package. When the envelope 16 permits passage of sterilizing agents in gaseous form, the entire envelope 16 as well as the inside of envelope 10 will be sterilized automatically by the escape in gaseous form of the sterilizing agent from the exibilizing fluid.

If desired, the positions of the two envelopes 10 and 16 in Fig. 3 may be reversed with the metal film-foil envelope 10 containing the suture reel and catgut liexibiliz.- ing fluid being the inner envelope while the outer envelope could be of any material capable of forming a bacteria impervious sealed envelope such as paper, film, and the like. It would be necessary to sterilize the outside of the foil envelope and the inside of the outer envelope, of course, by liquid or gaseous sterilization methods to get the advantages of the double envelope.

This latter construction permits taking the sterile inner envelope 10 into a sterile hospital area Vfrom which, if the envelope 10 is notropened and the suture used, it may be returned to be stored or have its outside resterilized in a sterilizing fluid Without harm to its inner contents.

In Fig. 4 another modification of Fig. 1 illustrates an essentially dry put-up with an absorbent material 18 placed in the envelope 10 or retained by the band 19 which is sealed into the package. The absorbent material 18 retains substantially all of the catgut suture liexibilizing fluid except that actually absorbed by the suture and that in vapor form in the envelope. The envelope 17 in Fig. 4 is shown unsealed but it may be omitted entirely or it may be similar to the envelope 16 in Fig. 3.

In Fig. 5 a further modification of Fig. 1 illustrates another essentially dry put-up with the suture reel 20 being sufliciently absorbent as to retain substantially all of the catgut suture flexibilizing liuid not absorbed by the suture or in the vapor form. This modification also illustrates that with thick foils of the order of .001 and more in thickness the film 15 may extend only in the area of the seal 26.

In Fig. 6, a glass jar 21 which serves as a shipping and storage container with a screw top 22 is shown containing a weight 23 carrying several clips 24 and holding sufficient quantity of sterilizing fluid Z5 to cover the sterile packages of sutures, liquids, or powders 10. The outsides of the metal film-foil packages are thus kept in sterile condition until the suture, liquid, or powder is to be made ready for use. Obviously, if the buoyancy of the packages is controlled so that packages will sink by themselves, holding clips or other submerging devices will not be necessary.

If it is desired to avoid adding sterilizing fluid to the Q jar 21 as sterile packages are removed, the level of sterilizing duid should be suiciently above the contained packages to compensate for the volume of the packages removed so that when only one package remains, the sterilizing fluid level will be such as to fully cover that remaining package.

However, if subsequent adding of sterilizing fluid is not objectionable, the jar 21 may be used as a dry shipping container whereupon sterilizing iluid may be added after receipt at the hospital. Obviously, the sterile packages must be fully covered with sterilizing uid to be unquestionably sterile, hence sterilizing fluid should be added when the level approaches that minimum.

I claim:

l. A composite article comprising an outer container impervious to formaldehyde and containing a formaldehyde sterilizing solution, a sterile non-frangible suture package housed in said container and immersed in said formaldehyde sterilizing solution, said suture package comprising opposing panels of formaldehyde impervious metallic foil having a heat-sealable lm interposed therebetween and presenting linear loci of contact with said solution, said lm being resistant to formaldehyde penetration therethrough and selected from the group consisting of alcohol insoluble polyamides, formaldehyde resins, polytrichlorouoroethylenes, polyethylene terephthalates, polymers and copolymers of vinyl esters, polymers and copolymers of vinylidene esters, plasticized rubber hydrochloride, polyacrylic polymers, butadienestyrene copolymers, butadiene-acrylonitrile copolymers, and polyethylene, and a sterile non-boilable catgut suture of surgically useable eXibility and strength heat-sealed in said package.

2. A composite article comprising an outer container impervious to formaldehyde and containing a formaldehyde sterilizing solution, a sterile non-frangible suture package housed in said container and immersed in said formaldehyde sterilizing solution, said suture package comprising opposing panels of formaldehyde impervious metallic foil having a heat-scalable film interposed therebetween and presenting linear loci of contact with said solution, said ilm being resistant to formaldehyde penetration therethrough and selected from the group consisting of alcohol insoluble polyamides, formaldehyde resins, polytrichlorouoroethylenes, polyethylene terephthalates, polymers and copolymers of vinyl esters, polymers and copolymers of Vinylidene esters, plasticized rubber hydrochloride, polyacrylic polymers, butadiene-styrene copolymers, butadiene-acrylonitrile copolymers, and polyethylene, suture tubing fluid and a sterile non-boilable catgut l@ v suture of surgically useable flexibility and strength heatsealed in said package.

3. A composite article as set forth in claim 2 further characterized in that said suture tubing fluid is an alcohol solution.

4. A composite article comprising an outer container impervious to formaldehyde and containing a formaldehyde sterilizing solution, a sterile non-frangible s'uture package housed in said container and immersed in said formaldehyde sterilizing solution, said suture package comprising opposing panels of formaldehyde impervious metallic foil having a heat-scalable vinyl polymer film interposed therebetween and presenting linear loci of contact with said solution, said film being resistant to formaldehyde penetration therethrough, and a sterile non-boilable catgut suture of surgically useable flexibility and strength heat-sealed in said package.

5. A composite article comprising an outer container impervious to formaldehyde and containing a fomnaldehyde sterilizing solution, a sterile non-frangible suture package housed in said container and immersed in said formaldehyde sterilizing solution, said suture package comprising opposing panels of formaldehyde impervious metallic foil having a heat-sealab-le vinyl copolymer lm interposed therebetween and presenting linear loci of contact with said solution, said lm being resistant to formaldehyde penetration therethrough, and a sterile non-boilable catgut suture of surgically useable flexibility and strength heat-sealed in said package.

6. A composite article comprising an outer container impervious to formaldehyde and containing a formaldehyde sterilizing solution, a sterile non-frangible suture package housed in said container and immersed in said formaldehyde sterilizing solution, said suture package comprising opposing panels of formaldehyde impervious metallic foil having a heat-scalable polyethylene film interposed therebetween and presenting linear loci of contact with said solution, said film being resistant to formaldehyde penetration therethrough, and a sterile non-boilable catgut suture of surgically useable exibility and strength heat-sealed in said package.

References Cited in the le of this patent UNITED STATES PATENTS 1,962,900 Hirsch June 12, 1934 2,121,988 Salsberg June 28, 1938 FOREIGN PATENTS 747,162 Great Britain Mar. 28, 1956 

